A 56 year old female patient was admitted to our hospital on July 10, 2020 due to palpitation, chest tightness and cough for more than 10 days. There was no obvious abnormality in the laboratory examination, including blood routine, liver and kidney function, pro-BNP, myocardial markers, C-reactive protein, coagulation function, tumor markers, sex hormone, rheumatism and rheumatoid factor. Chest CT indicated double pneumonia, pericardial effusion, bilateral pleural effusion. Echocardiography showed large left atrium with pericardial effusion. Pathological cytology of pericardial effusion showed more mesothelial cells, neutrophils and lymphocytes. The patient was discharged after the effective treatment of diuresis and anti-infection.
After discharge 11 days, the patient suffered from palpitation and chest tightness again. ECG examination showed AF (Figure 1) and the patient was hospitalized again. No obvious abnormalities were found in routine laboratory tests. Transesophageal echocardiography showed that enlargement of both atrium with mitral regurgitation and tricuspid regurgitation (AF associated) and atrial wall thickening.
On August 5, the patient underwent AF and AFL ablation. LASSO mapping showed that there was no potential activity in the left upper pulmonary vein, the right upper and lower pulmonary veins, the left atrium and left atrial appendage, but a small amount of potential in the left lower pulmonary vein (Figure 2). The atrial activation of AFL around the tricuspid annulus in the counterclockwise direction was mapped and part of the right atrium showed no potential activity. Circumferential left pulmonary veins and isthmus of tricuspid valve ablation were performed. After AFL converted to sinus rhythm, electrophysiological examination showed that the ablation line reached bidirectional block and AFL could not be induced (Figure 3).
We found that no pulsation of the ablation electrode during the circumferential left pulmonary veins ablation. So, an echocardiography expert reviewed the previous images and the parameters. The echocardiography indicated pericardial effusion, large left atrium, peak A can be seen in the blood flow spectrum of the mitral valve orifice during diastole on July 10. These results showed that the left atrium had contraction (Figure 4A, B). However, the results of echocardiography showed significant thickening of the wall of left atrial and left atrial appendage on August 3, there was no peak A in the blood flow spectrum of the mitral valve orifice during diastole. These results indicated that the left atrial had no contraction (Figure 4C,D).